Craniocervical junction involvement in ankylosing spondylitis.

PURPOSE: Available studies of craniocervical junction (CCJ) involvement in ankylosing spondylitis (AS) are based on conventional radiography, which has limited ability in the definition of many elements of the CCJ. The goal of the present study was to describe the spectrum of computed tomography (CT) findings in the CCJ in a cohort of patients with AS. METHODS: CT scans of the cervical spine of 11 patients with AS and 33 control subjects were reviewed, and imaging findings related to the CCJ were assessed. The standard anatomic intervals describing the CCJ were measured and compared to accepted normal standards. Findings representing pathology were described, categorized by localization, and relation to joints or ligaments of the CCJ. RESULTS: All AS patients were males with median age of 48 years and median disease duration of 20 years. The calculated median-modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS) for the cervical spine was 8.5 ranging from 0 to 27. Disease-related changes in one or more elements of the CCJ were detected in all patients. Atlanto-occipital joints were involved in 8 patients, while 3 patients had disease of the atlanto-dental articulation. Enthesopathy of the CCJ was observed in 7 patients. CONCLUSIONS: The CCJ is frequently involved in AS patients with advanced disease and may be independent on the mSASSS. Both articulations and ligaments of CCJ may be affected in AS patients.

Functional Capacity in Patients Who Recovered from Mild COVID-19 with Exertional Dyspnea.

BACKGROUND: Post mild COVID-19 dyspnea is poorly understood. We assessed physiologic limitations in these patients. METHODS: Patients with post mild COVID-19 dyspnea (group A) were compared (pulmonary function tests, 6-min walk test (6MWT), echocardiography and cardiopulmonary exercise test (CPET)) to post moderate/severe COVID-19 (group B) and to CPET and spirometry of patients with unexplained dyspnea (group C). RESULTS: The study included 36 patients (13 in A, 9 in B and 14 in C). Diffusion capacity was lower in group B compared to group A (64 ± 8 vs. 85 ± 9% predicted, p = 0.014). 6MWT was normal and similar in both patient groups. Oxygen uptake was higher in group A compared to groups B and C (108 ± 14 vs. 92 ± 13 and 91 ± 23% predicted, p = 0.013, 0.03, respectively). O2 pulse was normal in all three groups but significantly higher in the mild group compared to the control group. Breathing reserve was low/borderline in 2/13 patients in the mild group, 2/9 in the moderate/severe group and 3/14 in the control group (NS). CONCLUSIONS: Patients with post mild COVID-19 dyspnea had normal CPET, similar to patients with unexplained dyspnea. Other mechanisms should be investigated and the added value of CPET to patients with post mild COVID-19 dyspnea is questionable.

The chemokine stromal cell-derived factor-1α promotes endothelial progenitor cell-mediated neovascularization of human transplanted fat tissue in diabetic immunocompromised mice.

BACKGROUND: Stromal cell-derived factor-1α is a chemokine and mediates endothelial progenitor cell-induced neovascularization. Because vascularization of a graft is crucial for its survival, the authors investigated whether stromal cell-derived factor-1α could improve fat graft survival by inducing endothelial progenitor cell-mediated neovascularization and preventing its resorption. METHODS: The authors injected 1 ml of human fat tissue into the scalps of 30 diabetic and 10 nondiabetic immunocompromised mice. The fat grafts were treated with phosphate-buffered saline or stromal cell-derived factor-1α. Determination of graft phenotype included measurements of their weights and volumes, vascular endothelial growth factor (VEGF) levels, the stromal cell-derived factor-1α receptor CXCR4, VEGF receptor 2, endothelial nitric oxide synthase, serine/threonine-specific protein kinase (protein kinase B), caspase 3, and cytochrome c expression levels, and the extent of vascularization. RESULTS: Eighteen days after transplantation, stromal cell-derived factor-1α treatment of the grafts in the diabetic mice (1) increased plasma VEGF levels; (2) raised VEGF receptor 2, CXCR4, endothelial nitric oxide synthase, and protein kinase B expression levels; and (3) reduced caspase 3 and cytochrome c expression levels in the fat grafts. Fifteen weeks after transplantation, stromal cell-derived factor-1α treatment of the grafts prevented their resorption and increased the extent of their vascularization. CONCLUSION: Locally delivered stromal cell-derived factor-1α increases fat graft survival by stimulating neovascularization and reducing fat cell apoptosis through an endothelial progenitor cell-mediated mechanism.